* Updated Demo 7 for tiOPF.

* Added Demo 8 for tiOPF (still incomplete).

11 files changed, 901 insertions, 5 deletions

diff --git a/extras/tiopf/demos/Demo_06_CreateTable/demo_06.lpr b/extras/tiopf/demos/Demo_06_CreateTable/demo_06.lpr
index 7664dadf..3e97bf30 100644
--- a/extras/tiopf/demos/Demo_06_CreateTable/demo_06.lpr
+++ b/extras/tiopf/demos/Demo_06_CreateTable/demo_06.lpr
@@ -6,7 +6,7 @@ uses
   {$IFDEF UNIX}{$IFDEF UseCThreads}
   cthreads,
   {$ENDIF}{$ENDIF}
-  Classes, fpgfx, frm_main, tiOPFManager;
+  Classes, SysUtils, fpgfx, frm_main, tiOPFManager, tiConstants;
 
 
 procedure MainProc;
@@ -14,7 +14,12 @@ var
   frm: TMainForm;
 begin
   fpgApplication.Initialize;
-  
+
+  if GTIOPFManager.PersistenceLayers.FindByPersistenceLayerName(cTIPersistFBL) = nil then
+    raise Exception.Create('The system failed to find the <' + cTIPersistFBL + '> persistence layer')
+  else
+    GTIOPFManager.DefaultPersistenceLayerName := cTIPersistFBL;
+
   // Change the connection string to suite your database location
   // ** Remote connection
 //  gTIOPFManager.ConnectDatabase('192.168.0.54|/home/graemeg/programming/data/tiopf.fdb', 'sysdba', 'masterkey');
diff --git a/extras/tiopf/demos/Demo_07_VisitorBasics/demo_07.lpi b/extras/tiopf/demos/Demo_07_VisitorBasics/demo_07.lpi
index 2fcf4825..c07629aa 100644
--- a/extras/tiopf/demos/Demo_07_VisitorBasics/demo_07.lpi
+++ b/extras/tiopf/demos/Demo_07_VisitorBasics/demo_07.lpi
@@ -11,6 +11,7 @@
       </Flags>
       <SessionStorage Value="InProjectDir"/>
       <MainUnit Value="0"/>
+      <IconPath Value="./"/>
       <TargetFileExt Value=""/>
     </General>
     <VersionInfo>
diff --git a/extras/tiopf/demos/Demo_08_Collection/Client_AutoMap_Svr.pas b/extras/tiopf/demos/Demo_08_Collection/Client_AutoMap_Svr.pas
new file mode 100644
index 00000000..6ad1008e
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/Client_AutoMap_Svr.pas
@@ -0,0 +1,25 @@
+unit Client_AutoMap_Svr;
+
+{$mode objfpc}{$H+}
+
+interface
+
+procedure RegisterMappings;
+
+implementation
+uses
+   tiOPFManager
+  ,tiAutoMap
+  ,Client_BOM
+ ;
+
+procedure RegisterMappings;
+begin
+  //                                              Class,   Table,    Property,     Column,       Special Info
+  gTIOPFManager.ClassDBMappingMgr.RegisterMapping(TClient, 'Client', 'OID',        'OID',        [pktDB]);
+  gTIOPFManager.ClassDBMappingMgr.RegisterMapping(TClient, 'Client', 'ClientName', 'Client_Name'        );
+  gTIOPFManager.ClassDBMappingMgr.RegisterMapping(TClient, 'Client', 'ClientID',   'Client_ID'          );
+  gTIOPFManager.ClassDBMappingMgr.RegisterCollection(TClients, TClient);
+end;
+
+end.
diff --git a/extras/tiopf/demos/Demo_08_Collection/Client_BOM.pas b/extras/tiopf/demos/Demo_08_Collection/Client_BOM.pas
new file mode 100644
index 00000000..52775334
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/Client_BOM.pas
@@ -0,0 +1,70 @@
+unit Client_BOM;
+
+{$mode objfpc}{$H+}
+
+interface
+uses
+  tiObject
+  ;
+
+type
+
+  TClient = class;
+  TClients = class;
+
+  TClientName = String[200];
+  TClientID   = String[9];
+
+
+  TClients = class(TtiObjectList)
+  public
+    procedure Read; override;
+    procedure Save; override;
+  end;
+
+
+  TClient = class(TtiObject)
+  private
+    FClientID: TClientID;
+    FClientName: TClientName;
+  public
+    constructor CreateNew(const ADatabaseName: string=''; const APersistenceLayerName: string=''); override;
+  published
+    property    ClientName: TClientName read FClientName write FClientName;
+    property    ClientID: TClientID read FClientID write FClientID;
+  end;
+
+
+implementation
+uses
+   tiOPFManager
+  ,SysUtils
+  ,tiUtils
+  ;
+
+{ TClient }
+
+constructor TClient.CreateNew(const ADatabaseName: string = ''; const APersistenceLayerName: string = '');
+begin
+  inherited;
+  // Set some default values for the demo
+  ClientName := 'TEST ' + DateTimeToStr(Now);
+  ClientID := IntToStr(tiGetTickCount);
+end;
+
+{ TClients }
+
+procedure TClients.Read;
+begin
+  inherited Read;
+  NotifyObservers;
+end;
+
+procedure TClients.Save;
+begin
+  inherited Save;
+  NotifyObservers;
+end;
+
+end.
+
diff --git a/extras/tiopf/demos/Demo_08_Collection/Client_DBIndependentVisitors_Svr.pas b/extras/tiopf/demos/Demo_08_Collection/Client_DBIndependentVisitors_Svr.pas
new file mode 100644
index 00000000..495191e6
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/Client_DBIndependentVisitors_Svr.pas
@@ -0,0 +1,146 @@
+unit Client_DBIndependentVisitors_Svr;
+
+{$mode objfpc}{$H+}
+
+interface
+uses
+  tiVisitorDBAutoGen
+ ;
+
+type
+
+  TVisClient_Read = class(TVisDBAutoGenRead)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure Init          ; override;
+    procedure SetupParams   ; override;
+    procedure MapRowToObject; override;
+  end;
+
+  TVisClient_Create = class(TVisDBAutoGenUpdate)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure SetupParams   ; override;
+  end;
+
+  TVisClient_Update = class(TVisDBAutoGenUpdate)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure SetupParams   ; override;
+  end;
+
+  TVisClient_Delete = class(TVisDBAutoGenDelete)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure SetupParams   ; override;
+  end;
+
+procedure RegisterVisitors;
+
+implementation
+uses
+  Client_BOM
+  ,tiOPFManager
+  ,tiObject
+  ,tiLog
+  ,tiQuery
+ ;
+
+procedure RegisterVisitors;
+begin
+  gTIOPFManager.RegReadVisitor(TVisClient_Read);
+  gTIOPFManager.RegSaveVisitor(TVisClient_Create);
+  gTIOPFManager.RegSaveVisitor(TVisClient_Update);
+  gTIOPFManager.RegSaveVisitor(TVisClient_Delete);
+end;
+
+{ TVisClient_Read }
+
+function TVisClient_Read.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClients) and
+            (Visited.ObjectState = posEmpty);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Read.Init;
+begin
+  TableName:= 'Client';
+end;
+
+procedure TVisClient_Read.MapRowToObject;
+var
+  LClient: TClient;
+begin
+  LClient:= TClient.Create;
+  LClient.OID.AssignFromTIQuery('OID',Query);
+  LClient.ClientName:= Query.FieldAsString['Client_Name'];
+  LClient.ClientID:= Query.FieldAsString['Client_ID'];
+  LClient.ObjectState:= posClean;
+  TClients(Visited).Add(LClient);
+end;
+
+procedure TVisClient_Read.SetupParams;
+begin
+  // Do nothing
+end;
+
+{ TVisClient_Create }
+
+function TVisClient_Create.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClient) and
+            (Visited.ObjectState = posCreate);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Create.SetupParams;
+var
+  LData: TClient;
+begin
+  LData:= Visited as TClient;
+  TableName:= 'Client';
+  QueryType:= qtInsert;
+  QueryParams.SetValueAsString('OID', LData.OID.AsString);
+  QueryParams.SetValueAsString('Client_Name', LData.ClientName);
+  QueryParams.SetValueAsString('Client_ID', LData.ClientID);
+end;
+
+{ TVisClient_Update }
+
+function TVisClient_Update.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClient) and
+            (Visited.ObjectState = posUpdate);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Update.SetupParams;
+var
+  LData: TClient;
+begin
+  LData:= Visited as TClient;
+  TableName:= 'Client';
+  QueryType:= qtUpdate;
+  QueryWhere.SetValueAsString('OID', LData.OID.AsString);
+  QueryParams.SetValueAsString('Client_Name', LData.ClientName);
+  QueryParams.SetValueAsString('Client_ID', LData.ClientID);
+end;
+
+{ TVisClient_Delete }
+
+function TVisClient_Delete.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClient) and
+            (Visited.ObjectState = posDelete);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Delete.SetupParams;
+begin
+  inherited;
+  TableName:= 'Client';
+end;
+
+end.
+
diff --git a/extras/tiopf/demos/Demo_08_Collection/Client_HardCodedVisitors_Svr.pas b/extras/tiopf/demos/Demo_08_Collection/Client_HardCodedVisitors_Svr.pas
new file mode 100644
index 00000000..99a25573
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/Client_HardCodedVisitors_Svr.pas
@@ -0,0 +1,171 @@
+unit Client_HardCodedVisitors_Svr;
+
+{$mode objfpc}{$H+}
+
+interface
+uses
+  tiVisitorDB
+ ;
+
+type
+
+  TVisClient_Read = class(TVisOwnedQrySelect)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure Init          ; override;
+    procedure SetupParams   ; override;
+    procedure MapRowToObject; override;
+  end;
+
+  TVisClient_Create = class(TVisOwnedQryUpdate)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure Init          ; override;
+    procedure SetupParams   ; override;
+  end;
+
+  TVisClient_Update = class(TVisOwnedQryUpdate)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure Init          ; override;
+    procedure SetupParams   ; override;
+  end;
+
+  TVisClient_Delete = class(TVisOwnedQryUpdate)
+  protected
+    function  AcceptVisitor: boolean; override;
+    procedure Init         ; override;
+    procedure SetupParams   ; override;
+  end;
+
+procedure RegisterVisitors;
+
+implementation
+uses
+  Client_BOM
+  ,tiOPFManager
+  ,tiObject
+  ,tiLog
+ ;
+
+procedure RegisterVisitors;
+begin
+  gTIOPFManager.RegReadVisitor(TVisClient_Read);
+  gTIOPFManager.RegSaveVisitor(TVisClient_Create);
+  gTIOPFManager.RegSaveVisitor(TVisClient_Update);
+  gTIOPFManager.RegSaveVisitor(TVisClient_Delete);
+end;
+
+{ TVisClient_Read }
+
+function TVisClient_Read.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClients) and
+            (Visited.ObjectState = posEmpty);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Read.Init;
+begin
+  Query.SQLText:=
+    'select OID, Client_Name, Client_ID from Client';
+end;
+
+procedure TVisClient_Read.MapRowToObject;
+var
+  lClient: TClient;
+begin
+  lClient:= TClient.Create;
+  lClient.OID.AssignFromTIQuery('OID',Query);
+  lClient.ClientName:= Query.FieldAsString['Client_Name'];
+  lClient.ClientID:= Query.FieldAsString['Client_ID'];
+  lClient.ObjectState:= posClean;
+  TClients(Visited).Add(lClient);
+end;
+
+procedure TVisClient_Read.SetupParams;
+begin
+  // Do nothing
+end;
+
+{ TVisClient_Create }
+
+function TVisClient_Create.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClient) and
+            (Visited.ObjectState = posCreate);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Create.Init;
+begin
+  Query.SQLText:=
+    'Insert into Client (OID, Client_Name, Client_ID) ' +
+    'Values ' +
+    '(:OID,:Client_Name,:Client_ID)';
+end;
+
+procedure TVisClient_Create.SetupParams;
+var
+  lData: TClient;
+begin
+  lData:= Visited as TClient;
+  lData.OID.AssignToTIQuery('OID', Query);
+  Query.ParamAsString['Client_Name']:= lData.ClientName;
+  Query.ParamAsString['Client_ID']:= lData.ClientID;
+end;
+
+{ TVisClient_Update }
+
+function TVisClient_Update.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClient) and
+            (Visited.ObjectState = posUpdate);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Update.Init;
+begin
+  Query.SQLText:=
+    'Update Client Set ' +
+    '  Client_Name =:Client_Name ' +
+    ' ,Client_ID =:Client_ID ' +
+    'where ' +
+    ' OID =:OID';
+end;
+
+procedure TVisClient_Update.SetupParams;
+var
+  lData: TClient;
+begin
+  lData:= Visited as TClient;
+  lData.OID.AssignToTIQuery('OID', Query);
+  Query.ParamAsString['Client_Name']:= lData.ClientName;
+  Query.ParamAsString['Client_ID']:= lData.ClientID;
+end;
+
+{ TVisClient_Delete }
+
+function TVisClient_Delete.AcceptVisitor: boolean;
+begin
+  result:= (Visited is TClient) and
+            (Visited.ObjectState = posDelete);
+  Log([ClassName, Visited.ClassName, Visited.ObjectStateAsString, Result ]);
+end;
+
+procedure TVisClient_Delete.Init;
+begin
+  Query.SQLText:=
+    'delete from client where oid =:oid';
+end;
+
+procedure TVisClient_Delete.SetupParams;
+var
+  lData: TClient;
+begin
+  lData:= Visited as TClient;
+  lData.OID.AssignToTIQuery('OID', Query);
+end;
+
+end.
+
diff --git a/extras/tiopf/demos/Demo_08_Collection/demo_08.lpi b/extras/tiopf/demos/Demo_08_Collection/demo_08.lpi
new file mode 100644
index 00000000..9e6af029
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/demo_08.lpi
@@ -0,0 +1,94 @@
+<?xml version="1.0"?>
+<CONFIG>
+  <ProjectOptions>
+    <PathDelim Value="/"/>
+    <Version Value="6"/>
+    <General>
+      <Flags>
+        <SaveOnlyProjectUnits Value="True"/>
+        <MainUnitHasCreateFormStatements Value="False"/>
+        <MainUnitHasTitleStatement Value="False"/>
+      </Flags>
+      <SessionStorage Value="InProjectDir"/>
+      <MainUnit Value="0"/>
+      <IconPath Value="./"/>
+      <TargetFileExt Value=""/>
+    </General>
+    <VersionInfo>
+      <ProjectVersion Value=""/>
+    </VersionInfo>
+    <PublishOptions>
+      <Version Value="2"/>
+      <IncludeFileFilter Value="*.(pas|pp|inc|lfm|lpr|lrs|lpi|lpk|sh|xml)"/>
+      <ExcludeFileFilter Value="*.(bak|ppu|ppw|o|so);*~;backup"/>
+    </PublishOptions>
+    <RunParams>
+      <local>
+        <FormatVersion Value="1"/>
+        <LaunchingApplication PathPlusParams="/usr/X11R6/bin/xterm -T 'Lazarus Run Output' -e $(LazarusDir)/tools/runwait.sh $(TargetCmdLine)"/>
+      </local>
+    </RunParams>
+    <RequiredPackages Count="2">
+      <Item1>
+        <PackageName Value="fpgui_package"/>
+      </Item1>
+      <Item2>
+        <PackageName Value="tiOPFfpGUI"/>
+      </Item2>
+    </RequiredPackages>
+    <Units Count="7">
+      <Unit0>
+        <Filename Value="demo_08.lpr"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="demo_08"/>
+      </Unit0>
+      <Unit1>
+        <Filename Value="frm_main.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="frm_main"/>
+      </Unit1>
+      <Unit2>
+        <Filename Value="Client_HardCodedVisitors_Svr.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Client_HardCodedVisitors_Svr"/>
+      </Unit2>
+      <Unit3>
+        <Filename Value="Client_AutoMap_Svr.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Client_AutoMap_Svr"/>
+      </Unit3>
+      <Unit4>
+        <Filename Value="Client_BOM.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Client_BOM"/>
+      </Unit4>
+      <Unit5>
+        <Filename Value="Client_DBIndependentVisitors_Svr.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Client_DBIndependentVisitors_Svr"/>
+      </Unit5>
+      <Unit6>
+        <Filename Value="mediators.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="mediators"/>
+      </Unit6>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="5"/>
+    <Parsing>
+      <SyntaxOptions>
+        <AllowLabel Value="False"/>
+        <CPPInline Value="False"/>
+      </SyntaxOptions>
+    </Parsing>
+    <CodeGeneration>
+      <Generate Value="Faster"/>
+    </CodeGeneration>
+    <Other>
+      <CustomOptions Value="-FUunits
+-dUseCThreads"/>
+      <CompilerPath Value="$(CompPath)"/>
+    </Other>
+  </CompilerOptions>
+</CONFIG>
diff --git a/extras/tiopf/demos/Demo_08_Collection/demo_08.lpr b/extras/tiopf/demos/Demo_08_Collection/demo_08.lpr
new file mode 100644
index 00000000..de16545a
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/demo_08.lpr
@@ -0,0 +1,53 @@
+program demo_08;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}{$IFDEF UseCThreads}
+  cthreads,
+  {$ENDIF}{$ENDIF}
+  Classes, SysUtils, fpgfx, frm_main,
+  Client_DBIndependentVisitors_Svr, Client_BOM,
+  Client_AutoMap_Svr, Client_HardCodedVisitors_Svr, tiOPFManager,
+  tiConstants, mediators;
+
+procedure MainProc;
+var
+  frm: TMainForm;
+begin
+  fpgApplication.Initialize;
+
+  if GTIOPFManager.PersistenceLayers.FindByPersistenceLayerName(cTIPersistFBL) = nil then
+    raise Exception.Create('The system failed to find the <' + cTIPersistFBL + '> persistence layer')
+  else
+    GTIOPFManager.DefaultPersistenceLayerName := cTIPersistFBL;
+
+  { Change the connection string to suite your database location }
+  // ** Remote connection
+  //gTIOPFManager.ConnectDatabase('192.168.0.54|/home/graemeg/programming/data/tiopf.fdb', 'sysdba', 'masterkey');
+  // ** Local connection
+  gTIOPFManager.ConnectDatabase('/home/graemeg/programming/data/tiopf.fdb', 'sysdba', 'masterkey');
+
+
+  { Which persistence mechanism do you want to use? Uncomment one. }
+  Client_AutoMap_Svr.RegisterMappings;
+  //Client_HardCodedVisitors_Svr.RegisterVisitors;
+  //Client_DBIndependentVisitors_Svr.RegisterVisitors;
+
+
+  frm := TMainForm.Create(nil);
+  try
+    frm.Show;
+    fpgApplication.Run;
+  finally
+    frm.Free;
+    gTIOPFManager.DisconnectDatabase;
+    gTIOPFManager.Terminate;
+  end;
+end;
+
+begin
+  MainProc;
+end.
+
+
diff --git a/extras/tiopf/demos/Demo_08_Collection/frm_main.pas b/extras/tiopf/demos/Demo_08_Collection/frm_main.pas
new file mode 100644
index 00000000..eabcf56c
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/frm_main.pas
@@ -0,0 +1,310 @@
+unit frm_main;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  SysUtils, Classes, gfxbase, fpgfx, gui_edit, 
+  gfx_widget, gui_form, gui_label, gui_button,
+  gui_listbox, gui_memo, gui_combobox, gui_grid, 
+  gui_dialogs, gui_checkbox, gui_tree, gui_trackbar, 
+  gui_progressbar, gui_radiobutton, gui_tab, gui_menu,
+  gui_bevel, Client_BOM, mediators;
+
+type
+
+  TMainForm = class(TfpgForm)
+  private
+    FClients: TClients;
+    FmedClients: TClient_StringGrid_Mediator;
+    procedure   MainFormShow(Sender: TObject);
+    procedure   CreateTable;
+    procedure   DropTable;
+    function    TableExists: boolean;
+    procedure   btnInsertRowClick(Sender: TObject);
+    procedure   btnDeleteRowClick(Sender: TObject);
+    procedure   btnSaveClick(Sender: TObject);
+    procedure   btnReadClick(Sender: TObject);
+    procedure   btnShowClick(Sender: TObject);
+  public
+    {@VFD_HEAD_BEGIN: MainForm}
+    lblName1: TfpgLabel;
+    lblName2: TfpgLabel;
+    lblName3: TfpgLabel;
+    edtOID: TfpgEdit;
+    edtClientName: TfpgEdit;
+    edtClientID: TfpgEdit;
+    btnInsertRow: TfpgButton;
+    btnDeleteRow: TfpgButton;
+    btnShow: TfpgButton;
+    btnSave: TfpgButton;
+    btnRead: TfpgButton;
+    grdCollection: TfpgStringGrid;
+    {@VFD_HEAD_END: MainForm}
+    constructor Create(AOwner: TComponent); override;
+    destructor  Destroy; override;
+    procedure   AfterCreate; override;
+  end;
+
+{@VFD_NEWFORM_DECL}
+
+implementation
+
+uses
+   tiQuery
+  ,tiOIDGUID
+  ,tiOPFManager
+  ,tiDBConnectionPool
+  ,tiOID
+  ,tiDialogs
+  ,tiConstants
+  ;
+
+{@VFD_NEWFORM_IMPL}
+
+procedure TMainForm.MainFormShow(Sender: TObject);
+begin
+  // Drop and re-create to be sure we start with the correct structure
+  if TableExists then
+  begin
+    if TfpgMessageDialog.Question(ApplicationName, 'Must we delete existing data?', mbYesNo) = mbYes then
+    begin
+      DropTable;
+      CreateTable;
+    end;
+  end
+  else
+    CreateTable;
+end;
+
+procedure TMainForm.CreateTable;
+var
+  LTableMetaData: TtiDBMetaDataTable;
+begin
+  LTableMetaData := TtiDBMetaDataTable.Create;
+  try
+    LTableMetaData.Name:= 'Client';
+    LTableMetaData.AddField('OID',               qfkString,  36); // Using GUID OIDs
+    LTableMetaData.AddField('Client_Name',       qfkString, 200);
+    LTableMetaData.AddField('Client_ID',         qfkString,   9);
+    gTIOPFManager.CreateTable(LTableMetaData);
+  finally
+    LTableMetaData.Free;
+  end;
+end;
+
+procedure TMainForm.DropTable;
+begin
+  gTIOPFManager.DropTable('Client');
+end;
+
+function TMainForm.TableExists: boolean;
+var
+  LDBMetaData: TtiDBMetaData;
+  LDatabase: TtiDatabase;
+begin
+  LDBMetaData := TtiDBMetaData.Create;
+  try
+    LDatabase := gTIOPFManager.DefaultDBConnectionPool.Lock;
+    try
+      LDatabase.ReadMetaDataTables(LDBMetaData);
+      result := LDBMetaData.FindByTableName('Client') <> nil;
+    finally
+      gTIOPFManager.DefaultDBConnectionPool.UnLock(LDatabase);
+    end;
+  finally
+    LDBMetaData.Free;
+  end;
+end;
+
+procedure TMainForm.btnInsertRowClick(Sender: TObject);
+var
+  LClient: TClient;
+begin
+  LClient:= TClient.CreateNew;
+  FClients.Add(LClient);
+  //LV.Refresh(LClient);
+end;
+
+procedure TMainForm.btnDeleteRowClick(Sender: TObject);
+begin
+  //if LV.SelectedData <> nil then
+    //LV.SelectedData.Deleted:= true;
+  //LV.Refresh;
+end;
+
+procedure TMainForm.btnSaveClick(Sender: TObject);
+begin
+  FClients.Save;
+end;
+
+procedure TMainForm.btnReadClick(Sender: TObject);
+begin
+  FClients.Clear;
+  FClients.Read;
+  //LV.Refresh;
+  FmedClients := TClient_StringGrid_Mediator.CreateCustom(FClients, grdCollection, 'ClientName(200,"Client name");ClientID(80,"Client ID")');
+  FClients.NotifyObservers;
+end;
+
+procedure TMainForm.btnShowClick(Sender: TObject);
+begin
+  tiShowString(FClients.AsDebugString);
+end;
+
+constructor TMainForm.Create(AOwner: TComponent);
+begin
+  inherited Create(AOwner);
+  WindowTitle := 'Connected to ' + gTIOPFManager.DefaultDBConnectionName;
+  FClients := TClients.Create;
+  OnShow := @MainFormShow;
+  
+  //FmedClients := TClient_StringGrid_Mediator.CreateCustom(FClients, grdCollection, 'ClientName(200,"Client name");ClientID(80,"Client ID")');
+  //FClients.NotifyObservers;
+
+  //LV.AddColumn(LVDeriveOID, 'OID', 270);
+  //LV.AddColumn('ClientName', vttkString, 'Client name', 200);
+  //LV.AddColumn('ClientID',   vttkString, 'Client ID', 80);
+  //LV.Data:= FClients;
+end;
+
+destructor TMainForm.Destroy;
+begin
+  FmedClients.Free;
+  FClients.Free;
+  inherited Destroy;
+end;
+
+procedure TMainForm.AfterCreate;
+begin
+  {@VFD_BODY_BEGIN: MainForm}
+  Name := 'MainForm';
+  SetPosition(304, 254, 565, 250);
+  WindowTitle := 'Collection demo';
+  WindowPosition := wpScreenCenter;
+  Sizeable := False;
+
+  lblName1 := TfpgLabel.Create(self);
+  with lblName1 do
+  begin
+    Name := 'lblName1';
+    SetPosition(8, 12, 80, 16);
+    Text := 'OID:';
+    FontDesc := '#Label1';
+  end;
+
+  lblName2 := TfpgLabel.Create(self);
+  with lblName2 do
+  begin
+    Name := 'lblName2';
+    SetPosition(8, 36, 80, 16);
+    Text := 'Client Name:';
+    FontDesc := '#Label1';
+  end;
+
+  lblName3 := TfpgLabel.Create(self);
+  with lblName3 do
+  begin
+    Name := 'lblName3';
+    SetPosition(8, 60, 80, 16);
+    Text := 'Client ID:';
+    FontDesc := '#Label1';
+  end;
+
+  edtOID := TfpgEdit.Create(self);
+  with edtOID do
+  begin
+    Name := 'edtOID';
+    SetPosition(88, 8, 172, 22);
+    Text := '';
+    FontDesc := '#Edit1';
+  end;
+
+  edtClientName := TfpgEdit.Create(self);
+  with edtClientName do
+  begin
+    Name := 'edtClientName';
+    SetPosition(88, 32, 172, 22);
+    Text := '';
+    FontDesc := '#Edit1';
+  end;
+
+  edtClientID := TfpgEdit.Create(self);
+  with edtClientID do
+  begin
+    Name := 'edtClientID';
+    SetPosition(88, 56, 172, 22);
+    Text := '';
+    FontDesc := '#Edit1';
+  end;
+
+  btnInsertRow := TfpgButton.Create(self);
+  with btnInsertRow do
+  begin
+    Name := 'btnInsertRow';
+    SetPosition(268, 8, 143, 24);
+    Text := 'Insert object into list';
+    FontDesc := '#Label1';
+    ImageName := '';
+    OnClick := @btnInsertRowClick;
+  end;
+
+  btnDeleteRow := TfpgButton.Create(self);
+  with btnDeleteRow do
+  begin
+    Name := 'btnDeleteRow';
+    SetPosition(268, 36, 143, 24);
+    Text := 'Delete object in list';
+    FontDesc := '#Label1';
+    ImageName := '';
+    OnClick := @btnDeleteRowClick;
+  end;
+
+  btnShow := TfpgButton.Create(self);
+  with btnShow do
+  begin
+    Name := 'btnShow';
+    SetPosition(416, 8, 143, 24);
+    Text := 'Show Objects in list';
+    FontDesc := '#Label1';
+    ImageName := '';
+    OnClick := @btnShowClick;
+  end;
+
+  btnSave := TfpgButton.Create(self);
+  with btnSave do
+  begin
+    Name := 'btnSave';
+    SetPosition(416, 36, 143, 24);
+    Text := 'Save';
+    FontDesc := '#Label1';
+    ImageName := '';
+    OnClick := @btnSaveClick;
+  end;
+
+  btnRead := TfpgButton.Create(self);
+  with btnRead do
+  begin
+    Name := 'btnRead';
+    SetPosition(416, 64, 143, 24);
+    Text := 'Read list from DB';
+    FontDesc := '#Label1';
+    ImageName := '';
+    OnClick := @btnReadClick;
+  end;
+
+  grdCollection := TfpgStringGrid.Create(self);
+  with grdCollection do
+  begin
+    Name := 'grdCollection';
+    SetPosition(8, 96, 552, 148);
+    FontDesc := '#Grid';
+    HeaderFontDesc := '#GridHeader';
+  end;
+
+  {@VFD_BODY_END: MainForm}
+end;
+
+
+end.
diff --git a/extras/tiopf/demos/Demo_08_Collection/mediators.pas b/extras/tiopf/demos/Demo_08_Collection/mediators.pas
new file mode 100644
index 00000000..a316f32f
--- /dev/null
+++ b/extras/tiopf/demos/Demo_08_Collection/mediators.pas
@@ -0,0 +1,17 @@
+unit mediators;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  tiCompositeMediators;
+  
+type
+  TClient_StringGrid_Mediator = class(TCompositeStringGridMediator)
+  end;
+
+implementation
+
+end.
+
diff --git a/extras/tiopf/gui/tiCompositeMediators.pas b/extras/tiopf/gui/tiCompositeMediators.pas
index 34417aa8..cd8d3547 100644
--- a/extras/tiopf/gui/tiCompositeMediators.pas
+++ b/extras/tiopf/gui/tiCompositeMediators.pas
@@ -608,15 +608,19 @@ begin
 end;
 
 procedure TCompositeStringGridMediator.RebuildStringGrid;
+var
+  i: integer;
 begin
+  writeln('RebuildStringGrid');
   { This rebuilds the whole list. Not very efficient. }
-//  View.BeginUpdate;
+  View.BeginUpdate;
   try
     FMediatorList.Clear;
-//    View.Columns.Clear;
+    for i := View.ColumnCount to 1 do
+      View.DeleteColumn(i);
     CreateSubMediators;
   finally
-//    View.EndUpdate;
+    View.EndUpdate;
   end;
 
 //  { Do nothing. Can be implement as you see fit. A simple example is given